66726564 has 48 divisors (see below), whose sum is σ = 170553600. Its totient is φ = 20210176.

The previous prime is 66726563. The next prime is 66726587. The reversal of 66726564 is 46562766.

It is not an unprimeable number, because it can be changed into a prime (66726563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 277 + ... + 11555.

It is an arithmetic number, because the mean of its divisors is an integer number (3553200).

Almost surely, 2^66726564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66726564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85276800).

66726564 is an abundant number, since it is smaller than the sum of its proper divisors (103827036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66726564 is a wasteful number, since it uses less digits than its factorization.

66726564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11332 (or 11330 counting only the distinct ones).

The product of its digits is 362880, while the sum is 42.

The square root of 66726564 is about 8168.6329333616. The cubic root of 66726564 is about 405.6015325814.

The spelling of 66726564 in words is "sixty-six million, seven hundred twenty-six thousand, five hundred sixty-four".